Fix indent
extends models for changesets

Reduce codes
Refactor models
Show version changes
extends models for changesets

Reduce codes

Refactor models

Add view changes

Show version changes

Show user changes

Fix user
Show status changes
Fix show decorated string about changes
Show subject changes
extends models for changesets

Reduce codes

Refactor models

Add view changes

Show version changes

Show user changes

Fix user

Show status changes

Refactor capsule member values

Fix show decorated string about changes

Show category changes

Fix category

Show subject changes

Show tracker changes

Fix tracker
Show priority changes
Show private changes
Show estimated_hours changes
Show project changes
Add features
Merge branch 'changes' into development